Tristan Spurlock added 14 points, and Sykes finished with 21 points and 10 boards. Sykes, who hit 7 of 9 free throws, is shooting 88.4 percent (23 of 26) from the free-throw line in conference play after shooting 53.3 percent during nonconference play.
A 19-9 Mustangs run cut what was an 11-point deficit to 66-65 with just 1:49 remaining. But SMU (11-10, 1-5) could not overtake UCF, as Sykes and Kasey Wilson hit back-to-back layups while the Knights held the Mustangs scoreless the rest of the way.
The Mustangs, who entered allowing opponents to shoot just 39 percent, allowed UCF to shoot 46.4 percent (26-for-56).
Ryan Manuel had 17 for SMU, which has lost nine of its last 12 after starting the season 8-1.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.
Mike Brey is looking at former Notre Dame players to fill two assistant jobs that have opened up with the departures of Martin Ingelsby and Anthony Solomon.
Purdue's 2016-17 prospects got a jolt Wednesday when forward Caleb Swanigan announced he will return for his sophomore season.